Zhigang Dong

Mating behavior is critical for the reproduction of Hermetia illucens, but the effects of multiple mating on female fecundity remain poorly understood. This study systematically investigated mating and oviposition behavior, mating diel rhythm, mating frequency distribution, and the effects of different mating histories on female egg production and the egg hatching rate in H. illucens under controlled conditions. The behavioral sequence of courtship, copulation, and oviposition was described. To evaluate the reproductive consequences of mating frequency, females with different pre-pairing mating histories (unmated vs. once-mated) were paired with males with different mating histories (unmated vs. once-mated vs. twice-mated), and the egg mass per female and egg hatching rate were compared among treatments. Mating peaked on day 2 after emergence (77.3%), with two daily activity peaks at 09:00–11:59 and 14:00–16:59. Most individuals mated once or twice, with a maximum of four matings. Notably, 30.0% of males remained unmated, a proportion significantly higher than that of unmated females (10.6%). Mating history had no significant effect on egg mass per female or the egg hatching rate (p > 0.05): neither female mating frequency (unmated vs. previously mated once) nor male mating frequency (unmated vs. previously mated once vs. previously mated twice) significantly affected these reproductive outcomes. These results indicate that one successful mating can meet female fertilization requirements, with no additional reproductive advantage from multiple mating under unfed, single-oviposition-event conditions. The higher unmated rate in males than in females suggests that the proportion of males in production colonies can be appropriately reduced without compromising reproductive efficiency under the tested cage conditions; validation under larger-scale, higher-density production systems is still required.

The genus Aphytis (Hymenoptera: Aphelinidae) comprises ectoparasitoids of scale insects and includes many species of biological control importance. The proclia group is a major lineage within this genus, with seven species recorded in China, along with two morphologically closely related species. Based on specimens collected from Fuzhou, Fujian Province, we identified four species: A. hispanicus (Mercet), A. pinnaspidis Rosen & DeBach, and two new species, A. latarcuatus Wang & Huang, sp. n. and A. denticulatus Wang & Huang, sp. n. The two new species are described and illustrated, and host associations and distribution records for all four species are summarized. A complete checklist and a morphological key for the 11 Chinese species of the proclia group and its morphologically similar species are provided. Molecular phylogenetic analyses based on partial COI and 28S rDNA sequences support the delimitation of the two new species and reveal a distinct lineage comprising A. pinnaspidis and the two new species which are excluded from the proclia group. This study presents the first molecular phylogenetic analysis of Chinese members of the proclia group and its allied species and highlights the value of integrating morphological and molecular evidence in species group-level taxonomy.

Two new species of the genus Encarsia Förster (Hymenoptera: Aphelinidae), E. cinnamomi Wang & Huang, sp.n. and E. ophiopogonis Wang & Huang, sp.n., are described and illustrated from Fujian, China. The mitochondrial genomes of these two new species and E. diaspidicola are sequenced (14,049 bp, 14,746 bp and 14,849 bp, respectively), both showing a strong A + T bias (84.1%, 84.7% and 84.8% respectively). We infer the phylogenies of several Encarsia species of Aphelinidae and other family of Chalcidoidea based on PCG123 datasets using Bayesian inference (BI) and maximum likelihood (ML) methods. ML and BI analysis both support Aphelinidae formed a sister group to Torymidae.

In this paper, three new species of Aphelinus (Hymenoptera: Aphelinidae), Aphelinus jinshanensis Wang & Huang, sp.n., Aphelinus albimaculatus Wang & Huang, sp.n. and Aphelinus varius Wang & Huang, sp.n. are described and illustrated. Additionally, the japonicus group of Aphelinus is reviewed. The japonicus group is differentiated from all the known groups of these three subgenera by having a 3-segmented flagellum in the male. It is characterized by the following combination of features: antenna 6-segmented in the female, and 5-segmented in the male; body yellow, partly dark brown to black; the numerous setae on mid-lobe not arranged in symmetry; ovipositor short, and hypopygium not reaching to the apex of the gaster. Aphelinus varius Wang & Huang, sp.n. described here represents the second species assigned to the japonicus group. An identification key to the species of this group is provided. The relationships among these three new species are analyzed using a maximum likelihood phylogenetic tree based on cox1 sequences. While the evolutionary relationships of some species or groups remain uncertain due to weak statistical support for the relevant branches.

Seventeen species of the mali-group of Aphelinus (Hymenoptera: Aphelinidae) are reviewed worldwide, including three new species, and five previously described species in China. The mali-group was defined by a combination of characters: head and body dark with parts of metasoma pale; fore wing with a complete row of setae inside the linea calva, or also only with a few setae in the angle between the linea and marginal vein; legs with mesocoxae, metacoxae and metatibia dark, metafemur pale. In this paper, three new species, Aphelinus tuberocephalus Wang & Huang, sp.n., Aphelinus hainanensis Wang & Huang, sp.n. and Aphelinus ruellia Wang & Huang, sp.n., are described and illustrated, with notes on one species, Aphelinus coreae Hopper & Woolley, new to China. A revised key to species of the mali-group is provided. Mitochondrial (COI) partial sequences were obtained successfully for A. tuberocephalus, A. hainanensis, A. ruellia and A. coreae.